#!/usr/bin/env ruby

class Mapper

  # initialize a mapper with raw data.
  def initialize(line)
    # chomp will remove endline characters
    # split will split the line for every tab character \t
    # strip will remove whitespaces at begining and end of every words
    @data = line.chomp.split("\t").map(&:strip)
  end

  # this "switch" will determine if we are reading a GameLog or a UserLog line
  # in our example, it is sufficient to look whether @data has 2, or 3 values
  # for more complex cases, I'm sure you'll always find something ;)
  def log_type
    @log_type ||= if @data.size == 2
                :game_log
              else
                :player_log
              end
  end

  def game_log_output
    game_id   = @data[0]
    game_type = @data[1]

    [game_id, log_type, game_type].join("\t")
  end

  def player_log_output
    player_id = @data[0]
    score     = @data[1]
    game_id   = @data[2]

    [game_id, log_type, player_id, score].join("\t")
  end

  # the mapper result
  def output
    return game_log_output if log_type == :game_log
    return player_log_output
  end

  # the Map! class method
  def self.map!(line)
    puts Mapper.new(line).output
  end

end

ARGF.each do |line|
  Mapper.map!(line) unless line.chomp.empty? # map every non-empty line with our mapper
end